2011 Chevrolet Impala Owner's Manual - Page 204

8-2 Climate Controls 9 (Fan Control): Turn clockwise or counterclockwise to increase or decrease the fan speed. Positioning the knob between two modes can select a combination of those modes. If the airflow seems low when the fan is at the highest setting, the passenger compartment air filter may need to be replaced. There will be some airflow noticeable from the various outlets when driving, even with the fan in the off position. For more information, see Passenger Compartment Air Filter on page 8‑5 and Scheduled Maintenance on page 11‑2. Air Delivery Mode Control: Turn clockwise or counterclockwise to change the direction of the airflow inside the vehicle. Single Zone A. Fan Control B. Outside Air C. Temperature Control D. Recirculation E. Air Delivery Mode Control F. Air Conditioning G. Rear Window Defogger Temperature Control: For dual zone, turn the thumbwheels up or down to increase or decrease the temperature on the driver or the passenger side of the vehicle. For single zone, turn the knob clockwise or counterclockwise to increase or decrease the temperature.